The raw sewage discharged from human bodies is typically discharged into a sewage system by use of a flush toilet or the like and then flows into a river after being temporarily contained in a holding tank and purified therein. However, at events such as festivals, athletic events, fairs, meetings and the like, temporary toilet facilities must be provided for disposal of raw human waste.
Employed conventionally are movable temporary toilets, most of which have a tank for temporarily storing the raw sewage therein. However, the temporary toilets have the problem that the raw sewage contained in the tank must be sucked into a vacuum truck for collection and the collected raw sewage must be transferred to a raw sewage disposal purifying facility, which is laborious and time consuming and is unhygienic.
Transportation vehicles, such as trains, buses, vessels, etc., which operate over long distances are provided with a tank exclusively used for storing and holding the discharged raw sewage. The raw sewage in this tank is subjected to a deodorizing treatment by chemicals and thereafter is collected by a vacuum truck at a terminal or relaying point.
As mentioned above, the raw sewage in conventional temporary toilets or movable transportation facilities is contained as it is discharged from the human body and is collected thereafter. Accordingly, the storing method, the collection method and the disposal method are not modern and are very unhygienic. Accordingly, if the temporary toilet has been used for a long period of time, the discharged raw sewage remains in the tank, which cause a bad smell. Furthermore, since operators dislike disposing of the raw sewage, it is not preferable in view of modernization of maintenance of the temporary toilet.
In an attempt to ameliorate the above problems, there have been proposed several hygienic disposal methods. In one method, for example, chemicals are introduced into the tank where the raw sewage is contained to thereby prevent the generation of the bad smell and to effect sterilization of the sewage. This method, however, cannot be used for a long period of time because the chemicals become diluted and costs are high though it is often employed in transportation vehicles.
In another method, the raw sewage is contained in a bag made of vinyl and the like to prevent the diffusion of the bad smell. This method, however, requires a vinyl bag of large size and involves a high cost for disposal thereof, and it is troublesome to separate the raw sewage from the bag. A large-scale disposal facility is also required.
In still another method, the discharged raw sewage is directly dried by use of heat from a burner, etc. Since the primary component of raw sewage is the liquid component, a large amount of heat energy is required to remove the liquid component and it takes a long period of time to effect one time disposal of the raw sewage.
In view of the drawbacks of the conventional methods of disposing of the raw sewage, the present inventor proposed a disposing apparatus having the drying cauldron provided with stirring blades and heat-holding balls therein in which the raw sewage is stirred by the rotation of the stirring blades and heated by heat released by the heat-holding balls whereby the raw sewage is dried in a short period of time and the liquid component which is the primary component of raw sewage is evaporated as disclosed in Japanese Patent Nos. 63-124150 and 2-411577, U.S. Pat. Nos. 4,999,930, 5,058,213, 5,152,074, 5,230,164 and 5,257,466, and U.S. Pat. Application Ser. Nos. 07/809 962 filed Dec. 18, 1991 abandoned and replaced by continuation application Ser. No. 08/143,522, filed Oct. 26, 1993, now U.S. Pat. No. 5,418,982 and Ser. No. 07/985 556, filed Dec. 3, 1992, now U.S. Pat. No. 5,261,126.
According to the proposed disposal methods, the raw sewage is heated, evaporated in the drying cauldron and diffused into the ambient atmosphere. Before the liquid component is diffused, the components which cause bad smell are resolved by a catalyst so that the liquid water is diffused into the atmosphere as an odorless vapor. It was preferable to employ such a method in view of environmental hygiene and preservation even if such method is employed in crowded buildings and/or by throngs of people.
It is very hygienic to evaporate and diffuse the raw sewage contained in the airtight drying cauldron and such operations can be carried out systematically, which results in not causing a burden to the operators. It is necessary to stir the raw sewage which is contained in the airtight drying cauldron so as to heat and evaporate the raw sewage uniformly and residual substances which are not evaporated must be removed. There is employed the arrangement of a stirring blade for stirring the residual substances in the drying cauldron and a cleaning mechanism.
In the arrangement for providing the stirring blade, it is necessary to provide a rotary shaft which extends perpendicular relative to the drying cauldron, which increases the height of the apparatus as a whole and which makes the mechanism very large. There is a case that foreign matter which cannot be evaporated, such as a metallic ball-point pen, a belt, clothing, etc. are introduced into the drying cauldron. In such a case, when the raw sewage is stirred, the foreign matter enters a gap between the stirring blade and the drying cauldron, which prevents the stirring blade from rotating, and hence causes trouble. Since the rotary shaft and the stirring blade must be accommodated inside the drying cauldron, the limited inner space of the drying cauldron is occupied by these mechanisms. As a result, the inner space of the drying cauldron cannot be effectively utilized, which leads to inconveniences.
Under the circumstances, it is desired to develop a raw sewage disposal apparatus capable of utilizing the inner space of the drying cauldron without accommodating the rotary shaft and the stirring blade inside the drying cauldron and also capable of stirring the raw sewage and cleaning the drying cauldron.
The present invention provides a raw sewage disposal apparatus comprising a metallic heat-resistant container for accommodating raw sewage therein, an electromagnetic heater provided adjacent to the container for generating high-frequency electromagnetic wave, a rotary holder for rotatably holding the container about a vertical shaft hereof as a rotary shaft, a driving means for rotating the container, at least one spherical stirrer accommodated in the container, and at least one nonrotatable baffle having a lower end which extends to the portion adjacent to the bottom of the container so as to contact the stirrer.
According to the present invention, the drying cauldron per se containing the raw sewage therein can be rotated horizontally and spherical stirring balls are accommodated inside the drying cauldron. With such an arrangement, when the drying cauldron is rotated, the stirring balls contained in the drying cauldron are rotated so that the raw sewage is stirred. A heater unit having a high-frequency coil therein is disposed under the drying cauldron wherein the high-frequency electromagnetic wave is generated by the heater unit. The electromotive wave transmits to the drying cauldron and the inside of the stirring balls, so that the drying cauldron and the stirring balls per se generate heat by electromagnetic induction heating. As a result, the temperature of the raw sewage is increased.
In such a manner, when the heater unit is heated while the drying cauldron is rotated, the raw sewage contained inside the drying cauldron is heated while it is stirred so that the liquid component which is a primary component of the raw sewage can be evaporated as vapor. Residual substances such fibrous substances which cannot be evaporated from the raw sewage remain inside the drying cauldron upon completion of the drying operation of the raw sewage. The substances are sliced off when the stirring balls are rotated in the drying cauldron and then they are reduced to powder, eventually changed into dust. This dust is sucked in the same principle as a vacuum cleaner so that the powdered dust which remains inside the drying cauldron can be cleaned.
With such an arrangement of the drying cauldron, the inside structure of the drying cauldron is simplified, whereby a stirring blade, which has been employed in the prior art raw sewage apparatus, does not bite into the metallic foreign matter or clothing even if they are present into the drying cauldron so that the rotation of the drying cauldron is not obstructed. Further, the raw sewage is not stirred by the stirring blade so that the drying cauldron can be rotated with assurance without trouble. As a result, such raw sewage disposal apparatus can be used for a long period of time.